How to Receive Messages from an SQS Queue with AWS CDK and Typescript

Introduction

In this lesson, we will learn how to receive messages from an SQS Queue with AWS CDK and Typescript. We will cover the basics of setting up an SQS Queue, creating a CDK stack, and writing a Typescript script to receive messages from the queue. By the end of this lesson, you will have a working example of how to receive messages from an SQS Queue with AWS CDK and Typescript.

Prerequisites

Before we begin, there are a few prerequisites that you should have in place. First, you should have an AWS account and be familiar with the AWS Console. Second, you should have an understanding of the AWS CDK and be comfortable writing Typescript. Finally, you should have an understanding of the SQS Queue and how it works.

Setting up an SQS Queue

The first step in receiving messages from an SQS Queue with AWS CDK and Typescript is to set up an SQS Queue. To do this, log into the AWS Console and navigate to the SQS service. From there, click the “Create Queue” button.

On the next page, you will be asked to provide a name for your queue. Choose a name that is descriptive and easy to remember. Once you have chosen a name, click the “Create Queue” button.

Once the queue has been created, you will be taken to the queue’s details page. On this page, you will find the queue’s URL, which you will need later. Make sure to copy this URL and save it somewhere safe.

Creating a CDK Stack

The next step is to create a CDK stack. To do this, open a terminal window and navigate to the directory where you want to create the stack. Once you are in the directory, run the following command:

cdk init --language typescript

This command will create a new CDK stack in the current directory. Once the stack has been created, open the cdk.json file and add the following line:

"sqs": {
  "queueName": "<your-queue-name>"
}

Be sure to replace <your-queue-name> with the name of the queue you created earlier.

Writing the Typescript Script

Now that we have our CDK stack set up, we can write the Typescript script to receive messages from the queue. To do this, create a new file called receive-messages.ts in the src directory.

In this file, we will use the AWS SDK for JavaScript to receive messages from the queue. To do this, we will need to import the SQS class from the aws-sdk package. We will also need to import the QueueUrl class from the @aws-cdk/aws-sqs package.

import { SQS } from 'aws-sdk';
import { QueueUrl } from '@aws-cdk/aws-sqs';

Next, we will create an instance of the SQS class and pass in the queue URL.

const sqs = new SQS({
  apiVersion: '2012-11-05',
  region: 'us-east-1',
});

const queueUrl = new QueueUrl('<your-queue-url>');

Be sure to replace <your-queue-url> with the URL of the queue you created earlier.

Finally, we will write the code to receive messages from the queue. To do this, we will use the receiveMessage() method of the SQS class.

const params = {
  QueueUrl: queueUrl,
  MaxNumberOfMessages: 10,
};

sqs.receiveMessage(params, (err, data) => {
  if (err) {
    console.log(err);
  } else {
    console.log(data);
  }
});

This code will receive up to 10 messages from the queue. If there are no messages in the queue, the data variable will be null.

Deploying the Stack

Now that we have our CDK stack and Typescript script set up, we can deploy the stack. To do this, run the following command in the terminal:

cdk deploy

This command will deploy the stack to your AWS account. Once the stack has been deployed, you can run the receive-messages.ts script to receive messages from the queue.

Conclusion

In this lesson, we learned how to receive messages from an SQS Queue with AWS CDK and Typescript. We covered the basics of setting up an SQS Queue, creating a CDK stack, and writing a Typescript script to receive messages from the queue. By the end of this lesson, you should have a working example of how to receive messages from an SQS Queue with AWS CDK and Typescript.

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